Uptake, translocation and accumulation of the fungicide benzene kresoxim-methyl in Chinese flowering cabbage (Brassica campastris var. parachinensis) and water spinach (Ipomoea aquatica)

Benzene kresoxim-methyl (BKM) is an important methoxyacrylate-based strobilurin fungicide widely used against various phytopathogenic fungi in crops. Uptake, translocation and accumulation of BKM in vegetables remain unknown. This study was designed to investigate uptake, translocation, and accumulation of 14C-BKM and/or its potential metabolites in Chinese flowering cabbage and water spinach. 14C-BKM can be gradually taken up to reach a maximum of 44.4% of the applied amount by Chinese flowering cabbage and 34.6% by water spinach at 32 d after application. The 14CO2 fractions released from the hydroponic plant system reached 37.8% for cabbage and 45.8% for water spinach, respectively. Concentrations of 14C in leaves, stems and roots all gradually increased as vegetables growing, with relative 44.9% (cabbage) and 26.8% (water spinach) of translocated from roots to edible leaves. In addition, 14C in leaves was mainly accumulated in the bottom leaves, which was visualized by quantitative radioautographic imaging. The bioconcentration factor of 14C ranged from 7.1 to 38.2 mL g−1 for the cabbage and from 8.6 to 24.6 mL g−1 for the water spinach. The translocation factor of BKM ranged from 0.10 to 2.04 for the cabbage and 0.10–0.46 for the water spinach throughout the whole cultivation period, indicating that the cabbage is easier to translocate BKM from roots to leaves and stems than water spinach. In addition, the daily human exposure values of BKM in both vegetables were much lower than the limited dose of 0.15 mg day−1. The results help assess potential accumulation of BMK in vegetables and potential risk. [Display omitted] •14C labeling was applied for uptake of benzene kresoxim-methyl in vegetables.•Benzene kresoxim-methyl can be taken up by cabbage and water spinach.•The 14CO2 derived from the pesticide were detected by 37.8–45.8% in vegetables.•Cabbage was easier to translocate the pesticide to shoots than water spinach. This study assesses uptake and accumulation of BMK in vegetables and potential risk.